Realizing your period is late can be terrifying, especially if you think pregnancy is a possibility. And though it would be nice to have a magic pill to restart your period without concern, that isn’t quite how missed period pills work.

Keep reading to learn what missed period pills are, how they work, and what you need to know before taking them.

What are missed period pills?

Missed period pills are sometimes called period pills or late period pills. You may also hear this method called menstrual regulation or “bringing down” your period. Most people, however, refer to it by a name you probably know already: the abortion pill.

How do period pills work?

The terms “period pills” and “menstrual regulation” put the focus on the vaginal bleeding that happens after taking mife and miso. In reality, however, this is just a side effect. The true purpose is to end a pregnancy and expel the tissue from your uterus.

Mifepristone works by blocking a pregnancy hormone called progesterone. Without this hormone, your body won’t deliver oxygen and nutrients to the embryo. Often, the embryo will die before your body expels the pregnancy tissue. 

Misoprostol causes bleeding and contractions, starting a process similar to labor. Your uterus will shed its lining, along with the embryo and other pregnancy tissue. Since you are pregnant, this process is more like a miscarriage than a period. You should expect heavier bleeding and strong cramping in your uterus and abdomen in the days and weeks after taking the pills.

Most importantly, you should be prepared for complications that might require medical treatment.

Are missed period pills safe?

Missed period pills are not safe, but not for the reasons you might think. Like any medications, both mife and miso can cause severe complications that can put your life and health in danger. 

Sadly, some women take period pills because they’re scared to know if they are really pregnant. By using the pills without taking a pregnancy test, they hope they can avoid the mental pain that might come from having an abortion. But taking these medications without first confirming that you’re pregnant and before having an ultrasound may lead to greater risk.

 The dangers of taking the abortion pill to “bring back your period” include:

• Being too far along – The FDA has only approved the abortion pill for use through the first 10 weeks (70 days) of pregnancy. Taking it when your gestational age is further along increases your risk of severe complications. According to the American College of Obstetricians & Gynecologists, an ultrasound is the only way to accurately date a pregnancy.

• Having an incomplete abortion – The abortion pill sometimes fails to completely expel all of the pregnancy tissue. If any tissue remains in your uterus, you may experience dangerously heavy bleeding or an infection that may become life-threatening. You should call 911 or visit the emergency room immediately if you have any signs of a failed abortion.

• Having an ectopic pregnancy – Some pregnancies develop outside of the uterus, usually in the Fallopian tube. Since this organ wasn’t made to stretch like the uterus, the growing pregnancy may rupture and cause infections or internal bleeding. The abortion pill will end the pregnancy, but it won’t expel the tissue since it isn’t in the uterus. You may need surgery to remove the tissue and prevent a serious infection.

There are also risks if you take late period pills when you’re not pregnant. Generally, you should never take medication—especially high doses of prescription medication—when you don’t know that you need it. If your period is just a bit late, you don’t need to experience the heavier bleeding, more intense pain, and nausea that missed period pills cause.

Additionally, a late or missing period may be a sign that you are experiencing a serious health issue. You should visit a doctor to get answers and treatment, not take pills that will cause bleeding without addressing the real cause.